Fellow models Karlie Kloss, Joan Smalls, Georgia May Jagger and Lindsay Wixson joined the model-turned-underwear-designer at the party, as well as Harper's Bazaar US editor Derek Blasberg and of course the man of the moment, Olivier Rousteing.

Rosie looked stunning in a duck-egg blue chiffon dress with a lace bodice panel from the Balmain Resort 2014 collection.

Joan Smalls dressed down for the occasion, sporting her signature denim shorts and a grey Kenzo sweatshirt, whilst Karlie Kloss and Georgia May Jagger rocked the masculine trend, with Jagger in a white fitted blazer and matching trousers, and Kloss in a sleeveless tuxedo-style top and leather trousers.

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